Inertia tripping mechanism



Patented Feb. 24, 1948 INERTIA TRIPPING MECHANISM Jackson H. Pressley, Marion, Ind., assignor, by mesne assignments, to Farnsworth Research Corporation, a corporation of Indiana Application May 5, 1944, Serial No. 534,231

9 Claims.

This invention relates generally to automatic phonograph devices and is particularly directed to change-cycle controlling mechanisms actuated by the tone arm.

Conventional automatic phonograph devices include either an electrically operated device or a mechanically operated device for controlling a record-changing cycle. Such prior control means for governing the operation of a record-changing cycle has been found to be unduly complicated and impractical. One of the principal limitations in the electrically operated change-cycle devices has been the improper disposition of the tone arm switch which initiates a change cycle. In one typical conventional automatic phonograph, the tone arm switch is disposed on the reproducer head and actuated either by a means positioned on the base plate or by the spiral tripping groove of a record. Such prior art arrangements add excessive weight to the tone arm assembly which causes undue vertical wear upon the playing groove of a record.

In mechanically operated control mechanisms, lever means are usually employed in conjunction with a tone arm to initiate a change cycle whereby the playing groove of the record supplies the driving force for moving the lever means. This type of mechanism causes extreme lateral wear upon the groove of a record. Hence, it is seen that prior art mechanisms cause unwarranted injury to the groove of a record whereby the tone quality of a selection is impaired.

One of the objects of the invention is to provide in an automatic phonograph a novel electrical circuit for controlling an automatic phonograph mechanism.

Still another object of the invention is to provide in an automatic phonograph a novel tone arm switch whereby the wear upon the playing groove of a record is reduced to a minimum.

A still further object of the invention is to provide in an automatic phonograph a simple circuit to insure positive control of the recordchanging cycle.

In accordance with the present invention, there is provided an automatic phonograph having a tone arm, a record-changing mechanism and an electrical control circuit. Positioned in the tone arm, there is arranged an inertia switch. The tone arm upon entering the tripping groove provided on a record is oscillated, thereby to actuate the inertia switch and close a circuit to a relay which automatically energizes a solenoid operatively connected to the record-changing mechanism to start the record-changing cycle.

Cooperating with the record-changing mechanism there is provided a transfer switch to hold said circuit closed during the change cycle. The record-changing mechanism is also adapted at the end of the change cycle to actuate the transfer switch to de-energize the complete circuit. In the circuit there is also arranged an auxiliary means adapted to cooperate with the transfer switch to prevent the energization of the circuit after the change cycle is completed.

For a better understanding of the invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

In the accompanying drawings:

Fig. l is a top plan view of a record changer with parts cut away to illustrate one feature of the control means.

2 is a schematic bottom plan view of the record player showing the electrical circuit in relation to a part of a record-changing mechanism.

Referring to the drawings, the invention consists of an automatic phonograph apparatus having a base plate Iii upon which a turntable I2 is rotatably supported for holding a record i4. Adjacent the turntable ii there is positioned a pedestal l5, upon which is pivotally mounted for horizontal and vertical movement a tone arm l8, having a reproducing head 28, to which is secured a stylus 2!, adapted to track the playing groove of a record. For supporting a stack of unplayed records, there is provided a pair of record supports 22, which are secured to the base plate H3 and diametrically spaced with respect to the turntable i2.

The record-changing mechanism for controlling the movement of the tone arm and the changing of a record includes a cam gear 24 together with pinion gear 50. The cam gear 24 is securely fixed to theft 26 on the underside of base plate i6. Above the cam gear 24 there is arranged an arcuate member 30, pivotally mounted to the bottom of frame it by pin 28. The free end of member 30 is cam-shaped and is also provided with an armature 32 which is operatively associated with electromagnet 552. Intermediate the ends of the arcuate member 30, there is a fixed pin 34 biased by spring 35. Spring 36 is secured to the base plate iii by a pin 33. When electromagnet 32 is energized, it attracts lever 30 against the biasing action of spring 36. Upon the de-energization of electromagnet 82, spring with the record-changing mechanism.

36 returns lever 30 to its normal position as shown on the drawings.

Pivotally mounted on the cam gear 24, as at Ill, for rotation therewith in a plane vertical thereto, there is provided a clutch member 40, one end of which is in tripping engagement with the cam surface of member 30. The opposite end has an extension 42 for engaging a driving means subsequently to be described. The cam gear 24 is also provided with a circuit-controlling cam 49.

For carrying out a record-changing cycle, there is provided a pinion gear 50 fixed to the continuously rotating turntable shaft 52 and adapted to mesh with cam gear 24. The change cycle is terminated when the breached portion 68 on the cam gear breaks the driving connection between cam gear 24 and pinion 50 at the conclusion of a record-changing cycle. Fixed to shaft 52 above .pinion 50, is a pin 50 for engaging extension 42 when the clutch member 49 is operated thereby to move cam gear 24 into mesh with pinion 50.

A complete description of a similar record-changing mechanism appears in the U. S. patent of A. L. Knox, et al., No. 2,290,372, granted July 21, 1942.

Referring to Fig. 2, there is shown a complete change-cycle control circuit and its association In the circuit there is provided a tone arm switch 60, a relay 89, a trip magnet 82, a bimetallic transfer switch 84 and a power source 86.

Referring to Fig. 1, there is mounted within 1 the tone arm I8 a tone arm switch consisting of a flexible member 62 positioned for movement between contacts 64 and 66. Contacts 64 and 66 are mounted on insulator blocks 68 and I0. Intermediate the ends of member 82, there is provided a double contact I2 and 73. The flexible member 62 is anchored at one end to an insulator block M which is secured at the pivoted end of the tone arm I8 to move therewith. The free end of the flexible member 62 includes an inertia member '76 whereby, during oscillation of the tone arm I8, flexible member 62 remains in a relatively stationary position and contact 84' or contact 66 moves into engagement with one of the contacts I2, 13 on flexible member 62. It will be noted that switch 60 is positioned adjacent I the pivoted end of the tone arm I8. Therefore, the weight of the switch is principally effective at the pivoted end of the tone arm, and is borne mainly by the pedestal l6, thereby reducing to Switch 84 consists of an insulator block 00, a spring contact 94, bimetallic element 90 and a cooperating heating element or resistor 98 cona minimum the wear upon the groove of the record by stylus 2I.

nected to one another by conductors 92 and 93.

Spring contact 94 is provided with a stop I00 for limiting its upward movement. In cooperation with spring contact 99, there is arranged a contact I02 mounted on an insulator block I04. Conductor I06 connects contact I02 with conductor I08. As shown in the drawings, raised portion 46 on cam 40 maintains contacts 94 and. I02 in spaced relation during the reproduction cycle of a record.

In cooperation with the tone arm switch 00, electromagnet 82 and the switch 84, there is provided a relay 80 having an armature I20. Upon the energization of the relay, said armature is arranged to close a pair of fixed contacts I2! and I24 mounted on an insulator block I22.

The firstcircuit which initiates the record-- changing cycle and whereby the record-changing mechanism is put into operation consists of the following arrangement of the elements. Relay 89 is energized by a circuit which may be traced from power source 88 through conductor H9, tone arm switch 60, conductors H2 and H3, winding of relay 80, conductor I08 and I09, conductor 92, conductor 93, bimetallic element 96, spring contact 94, conductor H4 and back to source 80. It is to be noted that flexible member 62 may complete the circuit to relay 89 through either of the contacts 64 or 66 by the shunt conductor H6.

Upon the energization of relay 90, the armature I29 is attracted to close a circuit in parallel with conductors I08 and H3 of relay to the electromagnet 82. This circuit may be traced from conductor I08 of relay 89, conductor I28, winding of electromagnet 82, conductor I26, contact I24, armature I20, conductor H8, and back to conductor H3 of relay 80.

For maintaining a positive control of the record-changing cycle, there is provided in the first circuit a heating element 98, connected across the conductors I09 and H3 of relay 80.

Upon movement of the high point 96 of cam 44' during the record-changing cycle, spring contact 94 of switch 84 is released to engage contact I02. Thereupon a second circuit is energized to provide heating current for element98 and thereby to heat bimetallic element 96 and assure positive control of the record-changing cycle. This second circuit may be traced from power source 96, conductors H0 and I23, contact I2I, armature I20, conductors H8 and H3, resistor 98, conductors I09 and I06, contact I02, spring contact 9%, conductor H9 and back to power source 88.

Mode of operation oscillates. This motion of the tone arm I8 causes contact 00 or contact 96 of switch 60 to engage one of the contacts I2, I3 on flexible member 02, thereby energizing the first circuit to relay 80 and electromagnet 82 as hereinbefore described.

Upon the energization of electromagnet 82, armature 32 of arcuate member 30 is attracted, thereby releasing clutch 0 to allow extension 52 to drop into the path of revolving pin 59. Pin 59 kicks extension 92 and moves cam gear 24 into mesh with pinion 50, thereby initiating the operation of a record-changing cycle. A single revolution of cam gear 24 completes one recordchanging cycle. As cam gear 24 nears the end of a revolution, the outer end of clutch 40 comes in contact with the free end of lever 39, whereby clutch 40 is pivoted and extension 42 is elevated out of the path of revolving pin 59 and reset for another tripping operation. When breached portion 98 of cam grear 20 reaches pinion 50, the change cycle ends.

Upon movement of the cam gear 29, high point 46 of cam 49 causes the spring contact 94, operatively associated therewith, to close contacts 94 and I02, thereby energizing the second circuit as already described.

For a complete description of the operation of a similar record-changing mechanism, reference is again made to U. S Patent 2,290,372, A. L. Knox, et al., granted July 21, 1942.

During the energization of the circuits, element 98 is heated, whereby bimetallic contact 96 flexes away from spring contact 94 and remains in this position until after cam gear 24 is revolved back to'its initial starting position. X

The return of raised portion 46 on cam 2 to its starting position breaks contacts 94 and W2, thereby deenergizing the complete circuit. Meanwhile the tone arm engages the record just prior to the termination of the change cycle as described in the aforementioned Knox patent. The slow cooling of element as after the circuit is opened insures positive control by preventing reenergization of the circuit when contact a l is returned to its initial position. Upon cooling, bimetallic element 96 returns to its normal position in engagement with contact 94 as shown in the drawings. On completion of the succeeding record, bimetallic element 96 and contact 9d are in readiness to initiate another cycle of operation.

While there has been described what is at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed in the 1ppended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. In an automatic honograph includin a tone arm and a record-changing mechanism, electrical circuit comprising a tone arm switch, an electromagnet operatively associated with said changing mechanism adapted to start the recordchanging cycle upon energization thereof, a relay including a switch for energizing said electromagnet, said tone arm switch being responsive to the movement of the tone arm to energize said relay, transfer means responsive to the movement of said record-changing means to hold said relay energized during the change cycle, means associated with said record-changing mechanism to actuate said transfer means to de-energize said relay at the completion of the change cycle, and auxiliary means cooperating with said transfer means and adapted to prevent the energization of said relay after the change cycle is completed.

2. In an automatic phonograph including a tone arm and a record-changing mechanism, a first electrical circuit comprising a tone arm switch, a relay includin a switch, said relay being responsive to the closure of said tone arm switch, a second electrical circuit comprising an electromagnet operatively associated with said record-changing mechanism adapted to start the record-changing cycle upon closure of said relay switch, a transfer switch responsive to movement of said record-changing mechanism to hold said second circuit closed during the change cycle, means associated with said record-changing mechanism to open said circuits at the completion of the change cycle, and auxiliary means common to the first and second circuits and 010-. eratively associated with said transfer switch to automatically prevent the energization of said circuits after the change cycle is completed.

3. In an automatic phonograph including a tone arm and a record-changing mechanism, an electrical circuit comprising a tone arm switch, electroresponsive means operatively associated with said changing mechanism adapted to start the record-changing cycle upon energization thereof, said tone arm switch being responsive to the movement of said tone arm to energize said electroresponsive means, transfer switch means responsive to the movement of said recordchanging mechanism during the change cycle to hold said electroresponsive means energized, means associated with said record-changing mechanism to de-energize said circuit at the end of the change cycle, and auxiliary means cooperating with said transfer switch means to prevent the energization of said circuit after the change cycle is completed.

4. In an automatic phonograph including a tone arm and a record changing mechanism, an electrically operated change-cycle control system comprising a source of potential, switch means connected in series with said source and associated with said tone arm to be responsive to abnormal movement of said tone arm, electromagnetic means associated with said recordchanging mechanism for initiating its operation, an electrically operated main switch connected to said switch means and said source to be en-- ergized during abnormal movement of said tone arm for energizing said electromagnetic means, transfer switch means operatively associated with said record-changing mechanism to be moved thereby, an electroresponsive device normally connected to one side of said source by said transfer switch means and to the other side of said source by a connection common to said switch means and said main switch, and a transfer contact connected to said electroresponsive device, said electromagnetic means and said main switch and disposed in the path of movement of said transfer switch means whereby said device, sa1d electromagnetic means and said main switch are connected to said source when contact is broken between said device and said transfer switch means.

5. In an automatic phonograph including a tone arm and a record-changing mechanism, an electrically operated change-cycle control system comprising a source of potential, switch means connected in series with said source and associated with said tone arm to be responsive to abnormal movement of said tone arm, electromagnetic means associated with said recordchanging mechanism for initiating its operation, a relay comprising an armature, a coil and a pair of contacts, said coil being connected to said switch means and said source to be energized during abnormal movement of said tone arm, said pair of contacts being connected to said source and said electromagnetic means for energizing it when said relay armature is operated, transfer switch means operatively associated with said record-changing mechanism to be moved thereby, an electroresponsive device normally connected to one side of said source by said transfer switch means and to the other side of said source by a connection common to said switch cans and said relay armature, and a transfer contact connected to said electroresponsive device, said electromagnetic means and said relay coil and disposed in the path of movement of said transfer switch means whereby said device, said electromagnetic means and said relay coil are connected to said source when contact is broken between said device and said transfer switch means.

6. In an automatic phonograph including a tone arm and a record-changing mechanism, an electrically operated change-cycle control system comprising a source of potential, switch means connected in series with said source and associated with said tone arm to be responsive to abnormal movement of said tone arm, electromagnetic means associated with said record-changing mechanism for initiating its operation, a relay comprising an armature, a coil and a pair of contacts, said coil being connected to said switch .means and said source to be energized during abnormal movement of said tone arm, said pair of contacts being connected to said source and said .electroresponsive device, said electromagnetic means and said relay coil and disposed in the path of movement of said spring contact whereby said device, said electromagnetic means and said relay coil are connected to said source when contact is broken between said device and said spring contact.

'7. In an automatic phonograph including a tone arm and a record-changing mechanism, an electrically operated change-cycle control system comprising a source of potential, switch means connected in series with said source and associated with said tone arm to be responsive to abnormal movement of said tone arm, electromagnetic means associated with said record-changing mechanism for initiating its operation, a relay comprising an armature, a coil and a pair of contacts, said coil being connected to said switch means and said source to be energized during abnormal movement of said tone arm, said pair of contacts being connected to said source and said electromagnetic means for energizing it when said relay armature is operated, transfer switch means including a contact spring operatively associated with said record-changing mechanism to be moved thereby, a heating element, a thermostatic element normally in contact with said spring and associated with said heating element to be heated thereby and moved from its normal position, said heating element being normally connected to one side of said source by a connection common to said switch means and said relay armature and to the other side of said source by said thermostatic element and said contact spring in series, and a transfer contact connected to said heating element, ,said electromagnetic means and said relay coil and disposed in the path of movement of said spring contact whereby said element, said electromagnetic means comprising an armature, a coil and a pair of contacts, said coil being connected to said switch means and said source to be energized during abnormal movement of said tone arm, said pair of contacts being connected to said source and said electromagnet for energizing it when said relay armature is operated, transfer switch means including a contact spring operatively associated with said record-changing mechanism to be moved thereby, a heating element, a bimetallic element normally in contact with said spring and associated with said heating element to be heated thereby and moved from its normal position, said heating element being normally connected to one side of said source by a connection common to said switch means and said relay armature and to the other side of said source by said bimetallie element and said contact spring in series, and a transfer contact connected to said heating element, said electromagnet and said relay coil and disposed in the path of movement of said spring contact whereby said element, said electromagnet and said relay coil are connected to'said source when contact is broken between said bimetallic element and said spring contact.

9. In an automatic phonograph including a tone arm and a record-changing mechanism, an electrically operated change-cycle control system comprising a source of potential, switch means associated with said tone arm and including a pair of connected contacts in series with said source and a movable contact responsive to abnormal movement of said tone arm, an electromagnet associated with said record-changing mechanism for initiating its operation, a relay comprising an armature, a coil and a pair of contacts, said coil being connected to said movable contact and said source to be energized during abnormal movement of said tone arm, said pair of relay contacts being connected to said source and said electromagnet for energizing it when said relay armature is operated, transfer switch means including a, contact spring operatively associated with said record-changing mechanism to be moved thereby, a heating element, a bimetallic element normally in contact with said spring and associated with said heating element to be heated thereby and moved from its normal 1:0:ition, said heating element being first connected to one side of said source by a connection common to said movable contact and said relay armature and to the other side of said source by said bimetallic element and said contact spring in series, and a transfer contact connected to said heating element, said electromagnet and said relay coil and disposed in the, path of movement of said spring contact whereby said heating element, said electromagnet and said relay coil are connected to said source when contact is broken between said bimetallic element and said spring contact.

JACKSON H. PRESSLEY.

REFERENCES CETED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

